protecting the ozone layerfinal goal of effective global protection of the ozone layer is to be...

Solvents, coatings and adhesives

Protecting the

Ozone Layer

V o l u m e 2

UNEP

2 0 0 1U P DAT E

This booklet is one of a series of reports prepared by the OzonAction Programme of the United Nations Environment

Programme Division of Technology, Industry and Economics (UNEP DTIE). UNEP DTIE would like to give special thanks

to the following organizations and individuals for their work in contributing to this project:

United Nations Environment Programme (UNEP)

Ms. Jacqueline Aloisi de Larderel, Director, UNEP DTIE

Mr. Rajendra M. Shende, Chief, UNEP DTIE Energy and OzonAction Unit

Ms. Cecilia Mercado, Information Officer, UNEP DTIE OzonAction Programme

Mr. Andrew Robinson, Programme Assistant, UNEP DTIE OzonAction Programme

Editor: Geoffrey Bird

Design and layout: ampersand graphic design, inc.

Printed in Malta by Interprint Limited

This brochure is available on-line at www.uneptie.org/ozonaction/library/

© 2001 UNEP

This publication may be reproduced in whole or in part and in any form for educational and non-profit purposes without

special permission from the copyright holder, provided acknowledgement of the source is made. UNEP would appreciate

receiving a copy of any publication that uses this publication as a source.

No use of this publication may be made for resale or for any other commercial purpose whatsoever without prior

permission in writing from UNEP.

The technical papers in this publication have not been peer-reviewed and are the sole opinion of the authors. The

designations employed and the presentation of the material in this publication therefore do not imply the expression of

any opinion whatsoever on the part of the United Nations Environment Programme concerning the legal status of any

country, territory, city or area or of its authorities, or concerning delimitation of its frontiers or boundaries. Moreover, the

views expressed do not necessarily represent the decision or the stated policy of the United Nations Environment

Programme, nor does citing of trade names or commercial processes constitute endorsement.

ISBN: 92-807-2160-7

Solvents, coatings and adhesives

Protecting the

Ozone Layer

V o l u m e 2

UNEP

2 0 0 1U P DAT E

Contents

Foreword 3

Acknowledgements 4

Executive summary 5

Ozone depletion: an overview 6

The Montreal Protocol 8

Ozone-depleting solvents 12

Current status 14

Substitute solvents and not-in-kind technologies 19

Prospects for action: 22

• Electronics 22

• Precision cleaning 25

• General metal cleaning 27

• Dry cleaning 29

• Adhesives 30

• Coatings and inks 32

• Aerosols 33

• Miscellaneous uses 34

• Article 5 countries – choosing the best alternative 35

• Conservation and recovery 36

Reduction scenarios 38

Resources: 40

• Secretariats and Implementing Agencies 40

• Contact points 41

• Equipment and trade names 41

• Further reading 42

• Glossary 43

About the UNEP DTIE OzonAction Programme 45

About the UNEP Division of Technology, Industry and Economics 47

Foreword

When the Montreal Protocol on Substances that Deplete the Ozone Layer came into force, in 1989, it

had been ratified by 29 countries and the EEC, and set limits on the production of eight man-made

chemicals identified as ozone-depleting substances (ODS). By July 2001 there were more than 170

Parties (i.e. signatories) to the Protocol, both developed and developing countries, and production

and consumption of over 90 substances were controlled.

Linking these two sets of figures, which attest to the success of the Montreal Protocol, is a process of

elimination of ODS in which ratification of the Protocol was only a first step. It was recognized from

the start that the Protocol must be a flexible instrument and that it should be revised and extended to

keep pace with scientific progress. It was also recognized that developing countries would face

special problems with phase out and would need assistance if their development was not to be

hindered. To level the playing field, the developing countries were given extra time to adjust

economically and to equip. A Multilateral Fund (MLF) was also set up early in the process to provide

financial and technical support for their phase out efforts.

Exchanges of information and mutual support among the Parties to the Montreal Protocol – via the

mechanisms of the MLF – have been crucial to the Protocol’s success so far. They will continue to be

so in the future. Even though many industries and manufacturers have successfully replaced ozone-

depleting solvents with substances that are less damaging to the ozone layer or with ozone depleting

depleting-free technology, lack of up-to-date, accurate information on issues surrounding ODS

substitutes continues to be a major obstacle for many Parties, especially developing country Parties.

To help stimulate and support the process of ODS phase out, UNEP DTIE’s OzonAction Programme

provides information exchange and training, and acts as a clearinghouse for ozone related

information. One of the most important jobs of the OzonAction programme is to ensure that all those

who need to understand the issues surrounding replacement of ODS can obtain the information and

assistance they require. Hence this series of plain language reports – based on the reports of UNEP’s

Technical Options Committees (TOC) – summarizing the major ODS replacement issues for decision

makers in government and industry. The reports, first published in 1992, have now been updated to

keep abreast of technological progress and to better reflect the present situation in the sectors they

cover: refrigerants; solvents, coatings and adhesives; fire extinguishing substances; foams; aerosols,

sterilants, carbon tetrachloride and miscellaneous uses; and methyl bromide. Updating is based on

the 1998 reports from the TOCs and includes further information from the TOCs until 2000.

Updating of the reports at this point is particularly timely. The ‘grace period’ granted to developing

countries under the Montreal Protocol before their introduction of a freeze on CFCs came to an end in

July 1999. As developing countries now move to meet their Protocol commitments, accurate and up-

to-date information on available and appropriate technologies will be more important than ever if the

final goal of effective global protection of the ozone layer is to be achieved.

The publications in this series summarize the current uses of ODS in each sector, the availability of

substitutes and the technological and economic implications of converting to ODS-free technology.

Readers requiring more detailed information should refer to the original reports of the UNEP Technical

Options Committees (see Further Reading) on which the series is based.

PROTECTING THE OZONE LAYER • TECHNICAL BROCHURE UPDATES • SOLVENTS AND COATINGS

3

Acknowledgements

This report is based on the UNEP Solvents, Coatings and Adhesives Technical Options Report

(Nairobi, UNEP, 1998). Several members of the Committee contributed specific sector input (*) and

peer reviewed (**) this document to ensure that the plain language reflects accurately the much more

detailed information available in the original report. The report was written by Darrel Staley, Boeing.

2001 MEMBERS OF THE UNEP SOLVENTS, COATINGS AND ADHESIVES

TECHNICAL OPTIONS REPORT COMMITTEE

Co-chairs Affiliation Country

Dr. Mohinder P. Malik Lufthansa German Airlines Germany(Adhesives) *

Dr. Ahmad H. Gaber Egypt

Members Affiliation Country

Dr. Srinivas K. Bagepalli, General Electric United States

Mr. Mike Clark Mike Clark Associates United Kingdom (Dry Cleaning) *

Dr. B. Costes Aerospatiale Matra Airbus France

Mr. Brian Ellis ** Cyprus

Mr. Joe R. Felty Raytheon United States(Electronics) *

Dr. Mark Flid Research Institute “Sintez” Russian Federation

Mr. Yuichi Fujimoto Japan Industrial Conference for Ozone Layer Japan

Mr. Jianxin Hu Peking University China

Dr. William Kenyon Global Centre for Process Change Inc. United States(Electronics) *

Dr. A. Khan ** Indian Institute of Chemical Technology India

Dr. Stephen Lai Singapore Productivity and Standard Board Singapore

Mr. Seok Woo Lee National Institute of Technology and Quality Republic of Korea

Mr. Abid Merchant DuPont Fluoroproducts United States (Precision Cleaning) *

Mr. James Mertens Dow Chemical United States

Mr. Andre Orban EURO CHLOR Belgium (Metal Cleaning) *

Mr. Patrice Rollet Promosol France

Mr. Shunichi Samejima F2 Chemicals Limited United Kingdom

Mr. Hussein Shafa’amri Ministry of Planning Jordan

Mr. Darrel A. Staley Boeing United States (Overall author) *

Dr. John R. Stemniski ** United States

Mr. Peter Verge Boeing United States (Aerosols and Miscellaneous uses) *

Mr. Glenn Welcher Pratt Whitney United States

Mr. John Wilkinson Vulcan Materials Co. United States

Mr. Xavier HK Yoong Fairchild Semiconductor Malaysia


4

Executive summary

Industries in non-Article 5 countries have successfully complied with the production phase out of

ozone-depleting solvents that came into effect in 1996, with minor exceptions for solvent use allowed

under Essential Use Exemptions1. Carbon tetrachloride (CTC) was not used as an industrial solvent

and the 1,1,1-trichloroethane produced in 1995 has reached the end of its shelf-life, although there

may still be some recycled solvent in use. Stockpiled CFC-113 is still being relied on for some

applications but users are feeling increasing pressure to find alternatives as stockpiles run out. A very

small quantity of ozone-depleting solvents authorized for essential use is still produced. Aqueous and

semi-aqueous processes have successfully replaced ozone-depleting solvents in many applications. It

is estimated that a large percentage of users (about 50–60 per cent) have made the transition to

these alternatives. In electronics, ”no-clean” methods have taken over a large part of the solvents

market.

Although the phase out effort is going well in Article 5 countries, many challenges remain, including:

• identification of producers, importers and vendors of ozone-depleting solvents;

• identification of products that contain ozone-depleting solvents;

• identification of and assistance to users from many small and medium size enterprises in selecting

and converting to the most appropriate alternative (most difficult in the solvent sector);

• affordability of alternatives, including new or retrofit equipment and, in some cases, higher

operating expenses for the converted process.

The multitude of applications in a number of diverse industries has slowed phase out in the solvents

sector in Article 5 countries. A major effort remains for small and medium size enterprises which,

when taken collectively, consume the greatest volume of ozone-depleting solvents.

CTC, considered toxic and carcinogenic by environmental authorities in most non-Article 5 countries,

is widely used for various cleaning processes in developing countries. Often, cleaning with carbon

tetrachloride is done in inadequately sealed vapour degreasing machines or in open containers. Use

of CTC in emissive operations presents a serious threat to the health of workers due to its proven

toxic effects. There is an urgent need to prevent its use under such conditions.

Recently, two ozone-depleting brominated solvents have been commercially introduced:

bromochloromethane (CBM) and n-propyl bromide (nPB). These two substances are also blended

into solvent mixtures that are sold under many trade names. They are being marketed as substitutes

for ozone-depleting solvents (CFC-113, 1,1,1-trichloroethane, and HCFCs) as well as non-ozone-

depleting solvents (methylene chloride, trichloroethylene and perchloroethylene). CBM has high

toxicity and is now also a controlled substance under the Montreal Protocol. A TEAP Task Force has

recently (2001) recommended that nPB not be used pending further data on its toxicity and its effect

on the ozone layer. The UNEP Solvents Technical Options Committee does not recommend nPB as a

substitute for other ozone-depleting solvents. Environmentally preferable non-ozone-depleting

solutions exist for all of the cleaning applications for which nPB is being promoted.


5

1 Essential use exemptions currently allow the use of small quantities of 1,1,1-trichloroethane for manufacture ofsolid rocket motors, CFC-113 for maintenance of torpedoes, and for laboratory and analytical uses. In 2001,the Secretariat granted an emergency exemption for the use of OD solvents in testing of oil in water.

Ozone depletion: an overview

Most of the oxygen in the Earth’s atmosphere is in the form of molecules containing two oxygen

atoms, known by the familiar chemical symbol O2. In certain circumstances, three atoms of oxygen

can bond together to form ozone, a gas with the chemical symbol O3. Ozone occurs naturally in the

Earth’s atmosphere where its concentration varies with altitude. Concentration peaks in the

stratosphere at around 25–30 kilometres from the Earth’s surface and this region of concentration of

the gas is known as the ozone layer.

The ozone layer is important because it absorbs certain wavelengths of ultraviolet (UV) radiation from

the Sun, reducing their intensity at the Earth’s surface. High doses of UV radiation at these

wavelengths can damage eyes and cause skin cancer, reduce the efficiency of the body’s immune

system, reduce plant growth rates, upset the balance of terrestrial and marine ecosystems, and

accelerate degradation of some plastics and other materials.

A number of man-made chemicals are known to be harmful to the ozone layer. They all have two

common properties: they are stable in the lower atmosphere and they contain chlorine or bromine.

Their stability allows them to diffuse gradually up to the stratosphere where they can be broken down

by solar radiation. This releases chlorine and bromine radicals that can set off destructive chain

reactions breaking down other gases, including ozone, and thus reducing the atmospheric

concentration of ozone. This is what is meant by ozone depletion. The chlorine or bromine radical is

left intact after this reaction and may take part in as many as 100,000 similar reactions before

eventually being washed out of the stratosphere into the troposphere.


6

Effects of CFCs on stratoshperic ozone

UV radiation CFCl3

CFCl2

chlorineradical

chlorinemonoxide free

chlorineradical

ozone(O3)

series of reactions

oxygenmolecule

(O2)

+

When gases containing

chlorine, such as CFCs, are

broken down in the

atmosphere, each chlorine atom

sets off a reaction that may

destroy hundreds of thousands

of ozone molecules.

Another important environmental impact of a gas is its contribution to global warming. Global

Warming Potential (GWP) is an estimate of the warming of the atmosphere resulting from release of a

unit mass of gas in relation to the warming that would be caused by release of the same amount of

carbon dioxide. Some ODS and some of the chemicals being developed to replace them are known

to have significant GWPs. For example, CFCs have high GWPs and the non-ozone-depleting

hydrofluorocarbons (HFCs) developed to replace CFCs also contribute to global warming. GWP is an

increasingly important parameter when considering substances as candidates to replace ODS.

During past decades, sufficient quantities of ODS have been released into the atmosphere to damage

the ozone layer significantly. The largest losses of stratospheric ozone occur regularly over the

Antarctic every spring, resulting in substantial increases in UV levels over Antarctica. A similar though

weaker effect has been observed over the Arctic.

At present, scientists predict that, provided the Montreal Protocol is implemented in full, ozone

depletion will reach its peak during the next few years and will then gradually decline until the ozone

layer returns to normal around 2050.


7

number of carbon atoms minus one (omitted if 0)

CC

FF

FF

ClCl CFC 114

number of hydrogen atoms, plus one

number of fluorine atoms in one molecule

Note: 1. All spare valencies filled by chlorine atoms2. Different isomers are indicated by a suffic of lower case letters3. Bromine atoms are indicated by a suffic B plus number of atoms4. Hundreds number = 4 or 5 for blends (e.g. R-502)

CFC numbers provide the information

needed to deduce the chemical structure

of the compound. The digit far right

provides information on the number of

fluorine atoms, the digit second from the

right provides information on hydrogen

atoms, and the digit on the left provides

information on carbon atoms. Vacant

valencies are filled with chlorine atoms.

Adding 90 to the number reveals the

numbers of C, H and F atoms more

directly.

How CFC Nomenclature Works

The Montreal Protocol

The Montreal Protocol, developed under the management of the United Nations Environment

Programme in 1987, came into force on 1 January 1989. The Protocol defines measures that

Parties must introduce to limit production and consumption of substances that deplete the ozone

layer. The Montreal Protocol and the Vienna Convention – the framework agreement from which the

Protocol was born – were the first global agreements to protect the Earth’s atmosphere.

The Protocol originally introduced phase out schedules for five CFCs and three halons. However, it

was designed so that it could be revised on the basis of periodic scientific and technical

assessments. The first revisions were made at a meeting of the Parties in London, in 1990, when

controls were extended to additional CFCs and halons as well as to carbon tetrachloride and methyl

chloroform. At the Copenhagen meeting, in 1992, the Protocol was amended to include methyl

bromide and to control HBFCs and HCFCs. A schedule for phase out of methyl bromide was

adopted at the Vienna meeting in 1995, and this was later revised in 1997, in Montreal. In 1999, the

Parties met in Beijing, where they extended control to bromochloromethane. By July 2001, there

were 177 Parties to the Montreal Protocol and more than 90 chemicals are now controlled.


8

Ozone-depleting Major uses Ozone-depletion substance (ODS) potential (ODP)

Ozone-depleting substances (ODS) covered by the Montreal Protocol and their ozone-depletion potential (ODP)*

* Where ranges of ODP are given, readers requiring the exact ODP for a given CFC, halon, HBFC or HCFC shouldrefer to the Handbook for the International Treaties for the Protection of the Ozone Layer, published by the UNEPOzone Secretariat, or other accredited sources.

Chlorofluorocarbons

(CFC)

Refrigerants; propellants for spray cans, inhalers, etc.;

solvents, blowing agents for foam manufacture

0.6–1

Halons Used in fire extinguishers 3–10

Carbon tetrachloride

(CTC)

Feedstock for CFCs, pharmaceutical and agricultural

chemicals, solvent

1.1

1,1,1-trichlorethane

(methyl chloroform) Solvent 0.1

Hydrobromofluorocarbons

(HBFCs) Developed as ‘transitional’ replacement for CFCs. 0.01–0.52

Hydrochlorofluorocarbons

(HCFCs) Developed as ‘transitional’ replacement for CFCs. 0.02–7.5

Methyl bromide Fumigant, widely used for pest control 0.6

Bromochloromethane (CBM) Solvent 0.12

How regulation works

All ODS do not inflict equal amounts of damage on the ozone layer. Substances that contain only

carbon, fluorine, chlorine, and/or bromine – referred to as fully halogenated – have the highest potential

for damage. They include CFCs and halons. Other substances, including the hydrochlorofluorocarbons

(HCFCs), developed as replacements for CFCs, also contain hydrogen. This reduces their persistence

in the atmosphere and makes them less damaging for the ozone layer. For the purposes of control

under the Montreal Protocol, ODS are assigned an ozone-depletion potential (ODP).

Each controlled chemical is assigned an ODP in relation to CFC-11 which is given an ODP of 1.

These values are used to calculate an indicator of the damage being inflicted on the ozone layer by

each country’s production and consumption of controlled substances. Consumption is defined as

total production plus imports less exports, and therefore excludes recycled substances. The relative

ozone-depleting effect of production of a controlled ODS is calculated by multiplying its annual

production by its ODP, results are given in ODP tonnes, a unit used in this series of publications and

elsewhere. The ODS currently covered by the Montreal Protocol are shown, with their ODPs, in the

table on page 8.

Developing countries and the Montreal Protocol

From the outset, the Parties to the Montreal Protocol recognized that developing countries could face

special difficulties with phase out and that additional time and financial and technical support would

be needed by what came to be known as ‘Article 5’ countries. Article 5 countries are developing

countries that consume less than 0.3 kg per capita per year of controlled substances in a certain

base year. They are so called because their status is defined in Article 5 of the Protocol1.

Financial and technical assistance was provided under the 1990 London Amendment which set up

the Multilateral Fund (MLF). Activities and projects under the MLF are implemented by four

implementing agencies: UNDP, UNEP, UNIDO and the World Bank.

Article 5 countries were also granted a ‘grace period’ of 10 years to prepare for phase out. 1999

marked the end of that period for production and consumption of CFCs. Article 5 countries have,

since 1999, entered the ‘compliance’ period in which they will have to achieve specific reduction

targets.

The requirements of the Montreal Protocol as of December 2000 for both developed and Article 5

countries are shown in the table on page 10.


9

1 This is often written Article 5(1), indicating that status is defined in paragraph 1 of Article 5 of the Protocol.‘Article 5 Parties’ is also used.


10

Requirements of the Montreal Protocol including amendments and adjustments to the end of 1999**

Controlled Substance Reduction in consumption Reduction in consumption and production for and production for developing developed countries (Article 5) countries

CFC-11, CFC-12, CFC-113,

CFC-114, CFC-115

Base level: 1986

1989: Freeze

1994: 75 per cent

1996: 100 per cent

Base level: Average of 1995–1997

1999: Freeze

2005: 50 per cent

2007: 85 per cent

2010: 100 per cent

Halon 1211, halon 1301, halon

2402

Base level: 1986

1992: 20 per cent

1994: 100 per cent


2002: Freeze

2005: 50 per cent

2010: 100 per cent

Other fully halogenated CFCs Base level: 1989

1993: 20 per cent

1994: 75 per cent

1996: 100 per cent


2003: 20 per cent

2007: 85 per cent

2010: 100 per cent

Carbon tetrachloride Base level: 1989

1995: 85 per cent

1996: 100 per cent


2005: 85 per cent

2010: 100 per cent

1,1,1-trichloroethane

(methyl chloroform)

Base level: 1989

1993: Freeze

1994: 50 per cent

1996: 100 per cent


2003: Freeze

2005: 30 per cent

2010: 70 per cent

2015: 100 per cent

HCFCs Consumption

Base level: 1989 HCFC consumption +

2.8 per cent of 1989 CFC consumption

1996: Freeze

2004: 35 per cent

2010: 65 per cent

2015: 90 per cent

2020: 99.5 per cent

2030: 100 per cent

Production

Base level: 1989 HCFC consumption +

2.8 per cent of 1989 CFC consumption

2004: Freeze

Consumption

Base level: 2015

2016: Freeze

2040: 100 per cent

Production

Base level: 2015

2001: Freeze


11

Requirements of the Montreal Protocol including amendments and adjustments to the end of 1999**

Controlled Substance Reduction in consumption Reduction in consumption and production for and production for developing developed countries (Article 5) countries

** The Protocol allows some exemptions, e.g. for "essential uses." Readers requiring full details of phase out for a given substanceshould refer to the Handbook for the International Treaties for the Protection of the Ozone Layer, published by the UNEP OzoneSecretariat, or other accredited sources.

HBFCs 1996: 100 per cent 1996: 100 per cent

Bromochloromethane 2002: 100 per cent 2002: 100 per cent

Methyl bromide Base level: 1991

1995: Freeze

1999: 25 per cent

2001: 50 per cent

2003: 70 per cent

2005: 100 per cent

Base level: Average of 1995-1998

2002: Freeze

2005: 20 per cent

2003: review of reduction schedule

2015: 100 per cent

0

50

100

150

200

Beijing Amendment

Montreal Amendment

Copenhagen Amendment

London Amendment

Montreal Protocol

Vienna Convention

Agreement

No. of CountriesRatifying

Progress in the ratification of the Montreal Protocol and its amendments

*Source: Caleb Management. Senics, U.K.

Ozone-depleting solvents

CFC-113, 1,1,1-trichloroethane, carbon tetrachloride (CTC), and bromochloromethane (CBM) are

ozone depleting solvents controlled by the Montreal Protocol.

In the past, CFC-113 use was essential in many industrial applications: in electronic assembly

production processes, precision cleaning and general metal degreasing during manufacture, as well

as in dry cleaning and other industrial applications. CFC-113 began to be used in the 1970s in metal

degreasing and other areas owing to concern, particularly in the United States and Japan, over the

toxicity of the chlorinated solvents used previously. Its use in other sectors followed, contributing to a

rapid growth of the CFC-113 market, which reached 178,000 tonnes a year in 1986. CFC-113 has

an atmospheric residence time of 85 years and a relatively high ODP. It is a controlled substance

under the Montreal Protocol.

For many years 1,1,1-trichloroethane was the solvent of choice to replace other more toxic

chlorinated solvents for general metal cleaning. Early on in the phase out effort, it was considered a

likely substitute for CFC-113. However, it has been included as a controlled substance under the

Montreal Protocol since the 1990 revisions.

CTC is no longer used as a solvent in most countries because of its toxicity, but it is still used in some

parts of the world. It, too, is a controlled substance, and should not be substituted for CFC-113 or

1,1,1-trichloroethane. The ozone-depleting substances used as solvents are shown in the table

below.


12

Ozone-depleting substances used as solvents

GWP AtmosphericFormula ODP (100y) lifetime (years)

CFC-113 C2Cl3F3 0.8 5,000 85

1,1,1-trichloroethane CH3CCl3 0.1 140 4.8

CTC CCl4 1.1 1,400 35

HCFC 141b CH3CFCl2 0.11 700 9.2

HCFC 225ca CF3CF2CHCl2 0.03 180 2.1

HCFC 225cb CClF2CF2CHClF 0.03 620 6.2

Bromochloromethane (CBM) CH2BrCl 0.12

n-propyl bromide** CH3CH2CH2Br * < 1 < 1

* Unknown at this time but > 0. Currently under study.

** N-propyl bromide is not yet controlled by the Montreal Protocol.

CBM has been promoted as a precision cleaning solvent. The high toxicity of CBM is well known and

it has an ODP of 0.12. For these reasons alone, CBM should not be considered for any cleaning

application.

In recent years, HCFCs with lower ODPs have been developed as ozone-depleting solvent

substitutes in some uses. However, they also deplete the ozone layer and are now controlled under

the Montreal Protocol. HCFCs have later phase out dates than the three primary ODS. They are

currently used in some applications as a temporary solution and are therefore sometimes referred to

as transitional substances. As can be seen in the table on the previous page, 1,1,1-trichloroethane

and HCFC-141b have similar ODPs. For this reason, experts strongly advise against this conversion.


13

Current status

This section gives a baseline description of current ozone-depleting solvent use and an update on

remaining phase out challenges (usually in Article 5 countries). A more complete description of ozone-

depleting solvent applications can be found in the 1998 Assessment Report of the Solvent, Coatings

and Adhesives Technical Options Committee.

Electronics

The phase out of ozone-depleting solvents began much earlier in non-Article 5 countries, with the

production ban that came into effect on 1 January 1996. Both substitute solvents and not-in-kind

technologies have been implemented to replace CFC-113 and 1,1,1-trichloroethane-based solvent

formulations for post-soldering rosin and synthetic activated flux residue removal. Industry-wide

initiatives were undertaken to ensure that the new alternatives were compatible with the vast array of

metals, plastics, elastomers, adhesives and marking inks used. Industry trade organizations

undertook comprehensive studies of many technologies to ensure that the alternatives would provide

the same high level of electrical performance expected by electronics users.

Precision cleaning

Use of CFC-113 and 1,1,1-trichloroethane for precision cleaning applications has been essentially

eliminated in all non-Article 5 countries either by substitute solvents (e.g. HCFC, HFC, HFE and PFC)

or other not-in-kind technologies. HCFCs are relied on most heavily in this sub-sector because they

have properties very similar to the solvents previously used for these crucial cleaning operations, and

because they are more affordable than the other alternatives. For example, HCFC-225 has been used

with great success in military programme applications. However, as transitional substances, phase

out of these alternatives will ultimately be required as well.

HCFCs are also a popular alternative for precision cleaning applications in Article 5 countries because

they are much less expensive than the non-ozone depleting HFCs and HFEs. Where possible it is

always advisable to convert to a non-ozone depleting alternative and avoid the need for a future

conversion. Many not-in-kind alternatives exist for the Article 5 effort, but the equipment to support

these options tends to be expensive. Affordability will continue to be a concern for the Article 5 phase

out, especially for conversion projects in the precision cleaning sub-sector.


14

KEY FACTS

Precision cleaningapplications

• aircraft controls

• auto-pilot inertial naviagation systems

• auto-riveting

• gyroscopes

• maintenance cleaning

• medical equipment

• missile and satellite controls

• nuclear glove-boxdecontamination

• underwater systems


15

Current and future cleaning processes required for different electronics applications

Class Application Current Current non-ODS Future Possible future importance cleaning processes importance non-ODSof cleaning of cleaning cleaning processes

Note: Class 3, 2, or 1 denotes product classification by intended end-item use:Class 3: Continued high performance on demand where equipment must function when requiredClass 2: Continued, extended performance is desired but not criticalClass 1: Continued performance desired; non-function is an inconvenience

3 satellites

avionics instruments

avionics guidancesystems

submarinetelecommunications

medical life-support

cleaningessential

solvent or co-solvent orcombination solvents

semi-aqueous orsaponification cleaning(to military specificationsfor rosin fluxes)

cleaningessential

alcohol or various halogenatedor speciality solvents

saponifiers or water-solublesolvent or aqueous cleaning

controlled atmospheresoldering

3 automotive anti-lockbraking systems

automotive enginecontrol systems

landtelecommunications

high frequency & RFcircuits

cleaningessential

all cleaning methods toclean all flux types andfor ionic contaminants

cleaningessential

alcohol or various halogenatedor speciality solvents


controlled atmospheresoldering

3 sophisticated industrialcomputers

other automotive(except radio)

cleaningessential

all cleaning methods toclean all flux types andfor ionic contaminants(to military specificationrequirement levels)

cleaningessential


no-clean controlledatmosphere soldering

2 industrial machinerycontrols

medical non-life-support

cleaninggenerallyneeded

cleaningcould beminimized

solvent cleaning for rosinor resin fluxes

semi-aqueous orsaponification cleaningfor rosin or resin fluxes

cleaninggenerallyneeded

water soluble solvents

aqueous cleaning

no-clean controlledatmosphere soldering

2 low-cost instruments

office equipment

desktop and laptopcomputers

customer premisetelecommunications

automotive radio

TV EHT circuits

cleaningsometimesneeded

solvent or semi-aqueousor saponificationcleaning for rosin orresin fluxes

cleaningsometimesneeded

no-clean technologies usinglow-solids rosin fluxes

1 professional audio-visual equipment

quality consumer goods

automotiveentertainment

public address systems

cleaningnotrequired

rosin or resin fluxcleaning if required

cleaningrarelyneeded

no-clean technology using low-solids rosin fluxes

1 radio, television andother entertainment andhome electronics (massproduced)

cleaningnotrequired

nonecleaningnotperformed

no-clean technology using low-solids rosin (or other) fluxes

General metal cleaning

In the late 1990s, the metal forming and finishing industry of non-Article 5 countries completed

replacement of 1,1,1-trichloroethane and CFC-113 by substitute solvents or by aqueous and semi-

aqueous processes. Some Article 5 countries have also switched from ozone-depleting solvents in

general metal cleaning, but many challenges remain.

There is no single replacement method. Alternatives must be carefully selected and optimized for

each application, depending on the varying substrate materials, soils, cleanliness requirements,

process specifications and end uses.

While many alternatives reduce worker exposure to potentially harmful chemicals, the total cost –

including environmental concerns and socio-economic impact – should also be considered.

Furthermore, it has become clear that a significant use of CTC as a low cost, non-flammable solvent

for cleaning applications in Article 5 countries still remains.

Dry cleaning

The dry cleaning industry was never a large user of CFC-113, consuming less than 5 per cent of all

CFC-113. Its use has largely been eliminated as a result of replacement of CFC-113 dry cleaning

machines with new machines using perchloroethylene or hydrocarbon solvents. Only tail-end use

of residual stocks of CFC-113 in dry cleaning machines and some hand application of 1,1,1-

trichloroethane for stain removal remain. However, CTC is used for dry cleaning in some Article 5

countries.

Organic solvents are ideal for dry cleaning textiles because, unlike water, they do not distort fabrics.

CFC-113 was perfect because of its low toxicity, stability, mild solvency, non-flammability and

relatively low boiling point which minimizes energy requirements and reduces risk of heat damage to

sensitive fabrics. CFC-113 is used only in totally enclosed machines operating dry-to-dry processes.

The machines invariably incorporate sophisticated recovery systems to purify solvent for reuse and to

minimize solvent emissions.

Modern dry cleaning machines typically clean more than 50 kg of clothing for each litre of solvent

used. They are usually designed to operate with only one solvent and to last 12–15 years. They are

not easily convertible to alternative solvents, though some new machines can operate with a choice

of solvents. A machine represents the largest capital cost in setting up a dry cleaning operation.

Replacement with new machines that do not use CFC-113 may prove difficult for the small

businesses that predominate in this sector. For those machines remaining in use, improved operator

training, better housekeeping and maintenance practices will help maximize solvent mileage.

Perchloroethylene is the most widely used dry cleaning solvent, accounting for about 90 per cent of

the world’s dry cleaning. It has been used in this application for over 60 years and, although it has a

higher boiling point than CFC-113, the introduction of advanced heat exchange technology and

airflow dynamics has provided significant energy savings. Although some testing on rodents has

indicated a degree of carcinogenicity, it was concluded that the method of development was not

replicable in humans. Most authorities agree there is a very low risk to humans under normal

conditions of use.


16

Adhesives and coatings

1,1,1-trichloroethane has been the primary ozone-depleting solvent used in adhesive, coating, and

aerosol formulations. It is non-flammable, dries rapidly, does not significantly contribute to local air

pollution and performs well in many applications.

The total use of 1,1,1-trichloroethane in adhesives and coatings was always relatively small and has

now mostly been eliminated in the non-Article 5 countries. In Article 5 countries it is still being used,

but at a declining rate. A partial list of applications where 1,1,1-trichloroethane adhesives are used

includes packing, non-rigid bonding, rigid bonding, construction, tapes, transportation, and

consumer adhesives.

Aerosols

Solvents in aerosol product formulations function as either an active ingredient (e.g. degreaser or

cleaner) or as a solvent or carrier of other active substances. Though most ozone-depleting solvent

aerosol applications traditionally used 1,1,1-trichloroethane as their solvent, some products made use

of CFC-113, CFC-11, and CTC as well. Most uses of these four substances for aerosol products

have been replaced with alternative compounds, although considerable amounts are still used in

some Article 5 countries. Work is still underway to improve safety and flammability,

to alleviate health concerns, and to replace transitional alternatives such as HCFCs. There has also

been success in switching to alternative delivery methods that eliminate the need for an aerosol

package altogether.

Miscellaneous uses

There are a number of miscellaneous industrial and laboratory applications where some amounts

(relatively small quantities in most cases) of CFC-113, 1,1,1-trichloroethane, and CTC are employed.

In most cases, including cleaning of oxygen systems and detection of latent fingerprints, alternatives

are readily available and pose little further challenge. In other areas, such as laboratory testing and

space vehicle manufacturing, significant progress has been made but a complete phase out is still not

possible.


17

Article 5 countries

Phase out of ozone-depleting solvents is already initiated in Article 5 countries. A planned reduction

of consumption of the three controlled solvents has been initiated based on the total production in

respective countries. The phase out target is 2010 for CFC-113 and CTC. For 1,1,1-trichloroethane it

is 2015.

Phase out in developing countries has gone fairly well in the solvent sector, given the widespread use

of ozone-depleting solvents and the variety and complexity of the applications. Of the various sub-

sectors within the solvents sector, electronics and general metal cleaning have faced the greatest

challenge. The electronics industry has already made significant progress. This may be due to the

large number of electronics joint venture companies that have received assistance from their

experienced non-Article 5 partners. The large number of small users, many of whom are

undercapitalized, hampers the effort for metal cleaners.

Because of its low cost, non-flammability and good degreasing properties, CTC is widely used in

various general metal cleaning processes by large numbers of small users in Article 5 countries.

Typically, it is used in simple open containers where it presents not only a serious threat to the ozone

layer but, because of its proven toxic effects, a threat to the health of workers. Users have minimal

resources for change. Nevertheless, cleaning with CTC in open containers should not be allowed to

continue. Immediate substitution of trichloroethylene or perchloroethylene seems the most

appropriate short-term solution. Countries where CTC is still being used as a solvent need to develop

plans to assist users with the proper methods of use and disposal.


18

KEY FACTS

Miscellaneous ozone-depleting solvent usesinclude:

• Oxygen systems cleaning

• Detection of latent fingerprints

• Laboratory testing

• Space vehicle manufacturing

• Bearer media

• Semiconductor manufacturing

• Component drying

• Riveting and machining

• Aeroplane hydraulic system testing

• Leak detection

• Fabric protection and coating

• Mould release agents

• Motion picture film cleaning

• Military applications

• Vapour phase soldering

Substitute solvents and not-in-kind technologies

There is no single substitute for all uses of CFC-113 and 1,1,1-trichloroethane. Every solvent sub-

sector has at least one or more available alternatives. CFC-113 has been so widely used as a solvent

because it is suitable for many different applications. Any substitute for CFC-113 or 1,1,1-

trichloroethane should exhibit most, if not all, of their useful characteristics – particularly in cleaning

effectiveness. Substitutes should have a low ODP, GWP, and volatile organic content, as low toxicity

as possible, and not be carcinogenic. Recovery and recycling should also be possible. Alternative

processes should be cost effective and should not generate other environmental hazards.

An enterprise’s conversion strategy may include both short- and long-term plans for ozone-depleting

solvents. In the short term, recycling and recovery may constitute the first step. In the long term,

alternative processes and materials should be found since, because of losses, ozone-depleting

solvents cannot be recycled indefinitely. Emissions should be minimized by the use of closed

equipment.

Longer-term alternatives must be carefully monitored for environmental and health hazards. In

applications where toxic chemicals are the only current substitutes, their use will be permitted only

with strict workplace controls and until better substitutes are available.

A short description is given below of the general classes of alternatives available to replace ozone-

depleting solvents. Sector specific details follow this section.

Substitute solvents

Conventional non-ozone-depleting organic solvents (both halogenated and non-halogenated) are

excellent alternatives for many ozone-depleting solvent applications. Improved equipment and other

technical advances in recent years have extended the list of feasible applications for these well-known

solvents. Many of them are also attractive from a financial perspective. However, most non-

halogenated organic solvents that are useful for cleaning are also flammable or combustible. It is also

important to bear in mind that many of these solvents are classified as volatile organic compounds

(VOCs), which may restrict their emissive use in some geographic areas. In addition, vapour recovery

systems may be required to reduce worker exposure and environmental emissions. For these

reasons, this class of familiar alternatives requires careful consideration.


19

Hydrofluorocarbon (HFC) and Hydrofluoroether (HFE) formulations are now available to replace ozone-

depleting solvents. These solvents are an attractive solution because their physical properties are

similar to CFC-113 but they have no ODP. Because they are relatively weak cleaners, they are

typically combined with any of a number of other solvents to adjust their cleaning power and facilitate

soil removal. At this time, solvent blends containing HFC or HFE are still expensive. They also have

high GWPs.

Alternative solvent blends using HCFCs should be considered carefully. HCFC-141b and particularly

HCFC-225 are possible substitutes for CFC-113. However, they are only technically necessary for a

very small portion of CFC-113 applications. Although HCFC-141b is a possible substitute for 1,1,1-

trichloroethane, this substitution is strongly discouraged. The two solvents have the same ODP so

this switch offers no benefit. In general, the long atmospheric life and ODP of HCFCs mean that they

are not long-term substitutes for ozone-depleting solvents.

Perfluorocarbon (PFC) solvents are virtually inert and therefore have extremely long atmospheric

lifetimes and associated high GWPs. PFCs are extremely expensive and cleaning power is very low

except for a small range of soils. This class of substitute solvent should only be used as a last resort

in unique applications where emissions can be kept at or near zero.

The table overleaf lists some of the physical properties of the ozone-depleting solvents and their

halogenated substitute solvents.

Not-in-kind technologies

Although smaller, the list of not-in-kind alternatives is shorter than that of possible substitute solvents,

knowledge of proven not-in-kind technologies is extensive. Aqueous, semi-aqueous and emulsion

processes have successfully replaced ozone-depleting solvents in many applications. It is estimated

that a large percentage of users (about 50–60 per cent) have made the transition to these

alternatives. Aqueous processes, in general, use surfactants and additives with water. The semi-

aqueous and emulsion processes use hydrocarbon and surfactants plus additives followed by

aqueous rinsing.

”No-clean” methods have also taken a large percentage of the solvents market, particularly in the

electronics sector. The alternative is different for each sector, but generally it has meant production of

a new product (not maintenance) and usually requires significant changes to the manufacturing

process.


20

KEY FACTS

Ozone-depleting solventalternative requirements

• zero or low ODP• zero or low GWP• effective cleaner• low toxicity• non-flammable• low viscosity• non-corrosive• good recoverability• low operating cost• biodegradable

Select substitute solvent classes

• non-ozone-depleting halogenated organic

• non-ozone-depleting non-halogenated organic

• HFCs & HFEs• HCFCs• PFCs

Select not-in-kindtechnologies

• aqueous cleaning• semi-aqueous

cleaning• emulsion cleaning• "no-clean" alternatives


21

Properties of ozone-depleting solvents and selected halogenated solvent alternatives

Properties Formula ODP GWP Boiling Flash Surface Kauri- Toxicity(100y) point point tension Butanol

Halogenated solvent C C (dyne/cm) value1,1,1-trichloroethane & carbon tetrachloride substitutes

1,1,1-trichloroethane CH3CCl3 0.1 100 80 None 25 124 Low

carbon tetrachloride (CTC) CCl4 1.1 1,400 77 None 27 113 High

methylene chloride CH2Cl2 0 9 40 None 28 136 Med

perchloroethylene CCl2CCl2 0 ~ 9 121 None 31 90 Med

trichloroethylene CHClCCl2 0 < 9 87 None 29 129 Med

bromochloromethane CH2BrCl 0.12 68 None 132 High

n-propyl bromide CH3CH2CH2Br ** < 1 71 None 26 125 ***

CFC-113 substitutes

CFC-113 C2Cl3F3 0.8 6,000 48 None 17 32 Low

HCFC 141b CH3CFCl2 0.1 700 32 None 18 58 Low

HCFC 225ca CF3CF2CHCl2 0.03 180 54 None 16 34 Med

HCFC 225cb CClF2CF2CHClF 0.03 620 54 None 17 30 Low

HFC-43-10mee CF3CHFCHFCF2CF3 0 1,300 55 None 14 10 **** Low

HFE-449s1 C4F9OCH3 0 480 60 None 14 10 **** Low

PFC C6F14 0 7,400 56 None 12 Low

* CBM is not considered an alternative to 1,1,1-trichloroethane & carbon tetrachloride as it has high toxicity and is also a controlled substanceunder the Montreal Protocol. It is included for reference.

** Unknown at this time but > 0. Currently under study.

*** Currently under study.

**** Cleaning power increased with blends.

(CBM)*

Prospects for action

Electronics

Substitute solvents

Chlorinated solvents such as trichloroethylene (TCE) were used as a rosin flux residue cleaning agent

prior to the advent of 1,1,1-trichloroethane. TCE blends may be used, provided their use complies

with applicable regulations.

Brominated solvents such as n-propyl bromide (nPB) have been found to be good replacements for

1,1,1-trichloroethane, since the physical and chemical properties are almost an exact match.

However, this solvent is not recommended until its ozone-depleting and toxicity data are known.

Hydrochlorofluorocarbons (HCFC) such as HCFC 225 ca/cb and HCFC-141b are used in certain

applications as alternatives to CFC-113. HCFC-225 ca/cb has physical and chemical properties

almost identical to CFC-113 . However, the commercially available HCFC-225 ca/cb mixture now has

a higher toxicity than CFC-113. The new blend ratio, which will greatly facilitate applications such as

cleaning of oxygen lines and electronics components, has about the same toxicity level as TCE. Both

solvents are considered transitional as they have finite ODPs and thus will be phased out in the future.

Hydrofluorocarbon (HFC) and Hydrofluoroether (HFE) formulations are used to replace CFC-113

formulations. However, the zero ODP HFC-43-10mee and HFE 7100 are relatively weak cleaners

when used alone. These partially fluorinated solvents can be blended with various low molecular

weight alcohols (methanol, ethanol, propanols) as well as trans-dichloroethylene. This provides the

user with a wider selection of cleaning agents that can be tailored to the cleaning task. Typically, they

are combined with a number of other solvents to adjust their cleaning power to facilitate efficient flux

residue removal. They are also expensive and have GWP.

Non-ozone-depleting organic solvents used for electronics cleaning include terpenes, alcohols,

ketones, aldehydes and esters. These materials are effective in removing both solder fluxes and many

polar contaminants. Being flammable and classified as VOCs, they can be used only in small

quantities in well-ventilated areas in appropriate equipment. 2-Propanol (iso-propanol or IPA) is an

acceptable cleaner for some activated rosin fluxes. Special equipment required for flammable alcohol-

based solvents is commercially available including cold solvent cleaners, hot solvent cleaners, vapour-

phase batch cleaners, in-line cleaners and immersion cleaners. Most use ultrasonic agitation and/or

sprays to achieve more thorough cleaning.

Co-solvent systems are made up of a high-boiling ester and HFE combination in the washing stage,

followed by HFE in the rinsing and drying stage(s). The composition of the washing stage tank

controls the boiling point of the mixture, allowing the user to ‘mimic’ the boiling point of a number of

chlorinated solvents such as 1,1,1-trichloroethane, TCE and PCE.

Siloxanes contain silicon, oxygen and carbon. Such materials can be made with a range of boiling

points to meet specific needs. Although this has been achieved, many of the siloxanes are flammable,

requiring suitable equipment and cleaning procedures.


22

KEY FACTS

Substitute solvents:

• chlorinated solvents• hydrocarbon/surfact-

ant blends• organic solvents• alcohol-derived

solvents• solvent blends

Substitutetechnologies:

• aqueous cleaning • aqueous cleaning and

saponifier • aqueous cleaning and

hydrocarbon/surfact-ant blends

• light hydrocarbon solvent cleaning

• permitted halocarbon solvent cleaning

• no-clean technologies


Aqueous cleaning for water-soluble fluxes and pastes has now been used successfully for many

years in electronics manufacturing, so this technology is well accepted.

Aqueous cleaning, where alkaline organic or non-organic ‘saponifiers’ are mixed with water for

residue removal, has been in use for over 25 years. Recently, new saponifier formulations have

improved the process and now permit cleaning of some types of “no-clean” flux residues. This is

useful for companies wishing to standardize on using the same soldering chemistry for both cleaned

and uncleaned assemblies. Problems in using both types of aqueous technology are well known to

users. Some treatment of waste water may be required prior to discharge or disposal.

Semi-aqueous or Hydrocarbon/Surfactant (HCS) solvents are used to clean electronics assemblies to

remove rosin or synthetic activated flux residues, followed by water washing, rinsing and conventional

aqueous process drying. This process was first implemented in Article 5 countries when its capability

for cleaning surface mount technology was demonstrated. HCS are non-corrosive, have low viscosity

and foaming behaviour, remove both polar and non-polar contaminants, and are useful for cleaning

closely-spaced electronic assemblies at low temperatures. These materials are compatible with a

wide range of electronic materials of construction and have a neutral pH. Early formulations had fairly


23

KEY FACTS

Some 90 per cent of all solvent loss in theelectronics industrycould be eliminatedthrough conservation,recovery and recycling –at minimal net cost.

Available cleaning agent options for different electronic flux types

Brominated Chlorinated Partially Organic Speciality Water Water and Terpenes/Flux type solvent solvent fluorinated solvent solvent & saponfire hydrocarbons

solvent co-solvent and waterNon-activatedrosin* • • • • • - • •Mildly activatedrosin* • • • • • - • •Activated rosin** • • • • • • •Super-activatedrosin • • • • • - • •Water soluble*** - - - - • • •Synthetic activated*** **** **** • **** **** - - •Low solidsno cleaning - - - - - - - -required

* approved for US military use** approved for UK and US military use*** approved for UK military use**** not demonstrated

Notes: a) It is assumed the halogenated cleaning agents will be formulated with low molecular weight alcohol(s) for improved ionic residue removal.b) While the chlorinated solvent family includes MC, TCE, and PCE solvents, it is anticipated TCE will have the widest use for flux residueremoval.c) The ‘partially fluorinated solvent’ family includes HCFCs, HFCs and HFEs

low flash points, but the current formulations have high flash points, eliminating the need for some fire

suppression measures. These materials are classified as VOCs, thus their mists and vapours must be

properly contained. Waste streams from such processes may be hazardous and require proper

treatment or disposal. As this process combines both solvent and aqueous cleaning, capital and

operating costs are higher than for straight aqueous processes.

Aqueous emulsions of semi-aqueous cleaning agents have recently proven to be extremely effective

in cleaning electronics. Such emulsions can remove both rosin and synthetic activated flux residues

with the same effectiveness as other cleaning agents, although contaminant loading may be lower

than with other methods.

Low residue (“no-clean”) options include the use of low-solid fluxes and pastes in printed wiring

assembly (PWA) manufacture. These soldering materials can eliminate the need for cleaning

altogether in numerous applications, particularly in consumer and office electronics where a relatively

low level of cleanliness is acceptable. However, in high reliability applications, where extremely high

levels of cleanliness are required, all residues usually need to be removed.

Numerous new fluxes have been developed for wave soldering, containing 2-10 per cent solids as

opposed to the traditional 15-35 per cent solids. Many low-solid fluxes are non-corrosive and have

high surface insulation resistance. It is unnecessary to remove the minimal residues that may be left,

even for cosmetic purposes, resulting in material and operating cost savings – though existing

soldering machines may need modification. Further testing is required to determine the relevance of

this technology to the newest designs in different applications. High-solid fluxes requiring no post-

soldering cleaning have also been used. Low residue solder pastes for surface mount products,

based on ‘no clean’ flux technology, are also widely available. Their use is focused on the consumer

and business class of products where life is not at risk if the product fails in use.

Controlled atmosphere soldering is another cost-efficient, “no-clean” option. Two options are involved:

soldering in an inert gas or in a reactive gas. In the former, an inert gas such as dry nitrogen fills the

soldering chamber, displacing the air in preheated areas. Without oxygen, the solder forms minimal

amounts of oxides after soldering, so solder dross can be reduced by as much as 90 per cent

compared to normal soldering. Maintenance time is greatly reduced. Reactive atmosphere soldering

uses a reactive agent in an inert gas to reduce oxide layer formation on circuit boards.


24

Precision cleaning

Substitute solvents

The fluorinated substitutes for CFC-113 are HCFCs, HFCs, HFEs and PFCs. They all have similar

properties including excellent compatibility with most metals and plastics.

HCFCs (225 and 141b) were available at the time of CFC-113 phase out in non-Article 5 countries

and were readily adopted for some applications. However, these compounds have finite ODP and are

now scheduled for phase out, although not until 2030 for non-Article 5 countries and 2040 in Article 5

countries. In most cases, HCFCs will be replaced with HFCs, HFEs and their formulations.

Hydrofluorocarbons (HFC-43-10mee) and Hydrofluoroethers (C4F9OCH3 and C4F9OC2H5) were

introduced in the mid 1990s as substitutes for CFC-113 in precision cleaning applications. These

compounds have zero ODP, low toxicity and excellent material compatibility, but are expensive. HFCs

and HFEs do have GWP but it is lower than CFC-113 and PFCs. They are also commercially available

in many blends (azeotropes) with alcohols, hydrocarbons and chlorocarbons to increase cleaning

power for specific soils.

Perfluorocarbons (PFCs) were introduced in some CFC-113 applications before HFCs and HFEs

became available. PFCs have very high GWP, are very expensive and should only be considered

where other available substitutes cannot be used. PFCs are now being replaced with lower GWP,

HFCs, and HFEs in some applications.

Chlorocarbons (perchloroethylene, methylene chloride and trichloroethylene) are used as a substitute

for 1,1,1-trichloroethane in some precision cleaning applications. However, these compounds have

higher toxicity and could also raise compatibility issues. In some countries, trichloroethylene and

perchloroethylene are regulated as VOCs that contribute to tropospheric ozone formation, although

the effect of trichloroethylene is very small compared with most other volatile solvents.

Trichloroethylene, perchloroethylene and methylene chloride may be used, subject to applicable

regulations regarding operator exposure levels and environmental hazards.

Aliphatic hydrocarbons (such as mineral spirits, n-paraffin and kerosene) can be used as substitutes

in some processes involving hydrocarbon oils and greases. However, these compounds require

flammable rated equipment. Also, recovery processes such as carbon adsorption may be required to

reduce their emission as many aliphatics are classified as VOCs.

Alcohols and ketones can also be used in precision component cleaning, subject to material

compatibility and use of flammable rated equipment.

n-Propyl bromide (nPB) was recently introduced as an alternative to 1,1,1-trichloroethane for precision

cleaning. The physical and cleaning properties of this compound are comparable. However, it has

questionable toxicity and ODP and, until these issues are resolved, its use is discouraged.


25


The most popular not-in-kind technologies for precision cleaning are aqueous and semi-aqueous

processes. Aqueous processes, in general, use surfactants and additives with water. The semi-

aqueous and emulsion processes use hydrocarbon and surfactants plus additives followed by

aqueous rinsing. Both, aqueous and semi-aqueous processes involve the use of spray, mechanical

agitation and/or ultrasonics. Additional equipment such as heaters, filters, automation equipment,

recycling, and water treatment may be required. The cleaned parts are generally hot-air and/or

vacuum-oven dried. Such a rapid, potentially energy-intensive drying or de-watering process is

necessary. Most aqueous and semi-aqueous processes also require more floor space than solvent

processes.

Supercritical fluids (CO2) are gases held above the critical temperature and pressure at which they

would normally condense. Such gases are good solvents but can only be used in speciality

applications because they involve high-pressure systems and require substantial capital funds.

Plasma cleaning is used in a very selective cleaning application: that of precision instruments. Plasma

cleaning is only a viable option in special circumstances since it must often be preceded by solvent

cleaning to achieve an ultra-clean surface. It should therefore be considered a second step or

‘polishing’ cleaning process.

Ultraviolet (UV) light combined with ozone is also used in some speciality applications, to remove

organic films from surfaces (glass, quartz, sapphire, ceramics, metals, silicon and polyamide cement).


26

KEY FACTS

Substitute solvents forCFC-113:

• HCFCs and Blend• PFCs • HFC-43-10mee and

blends• HFEs (C4F9OCH3

and C4F9OC2H5) and blends

Substitute solvents for1,1,1-trichloroethane:

• Chlorocarbons (PCE, • MH2Cl2, and C2HCl3)• Hydrocarbons

(aliphatic and oxygenated)

• n-propyl bromide

Not-in-kindtechnologies:

• Aqueous and semi-aqueous cleaning

• Supercritical fluid cleaning and CO2snow

• Plasma cleaning• UV/ozone cleaning


27


Substitute solvents

Where metal substrates (such as aluminium or mild steel parts) could be corroded by acidic or

alkaline not-in-kind technologies or where parts are heavily contaminated, trichloroethylene,

perchloroethylene and methylene chloride are the most obvious alternatives to 1,1,1-trichloroethane.

They have similar physical and chemical properties, are inexpensive, and require only minor

modifications of the cleaning process.

Other commercially available substitute solvents for CFC-113 include HCFCs, HFCs, HFEs and their

blends. HCFC blends need improved recovery, handling and storage facilities due to their low boiling

points. This increases emissions during cleaning. Most non-Article 5 countries are phasing out HCFCs

because of their ODP. HFCs and HFEs are expensive, have low solvency and need the addition of a

more potent co-solvent. Many of these products are being regulated because of their GWP and/or as

VOCs in some countries.

Low cost hydrocarbon solvents and their oxygenated derivatives are increasingly used in specialized

equipment designed to prevent potential flammability and explosion hazards. These systems allow the

use of a large number of solvents. However, hydrocarbon and oxygenated solvents are often

Cold Hot Vapor High Manual Airtight Lowimmersionc immersionc decreasing pressure flash

Substitute spray point

Alkaline Cleaners • • • •Alternative Chlorinated

Solvents • • • • •d •Co-Solvent Cleaners • • • •Emullsion Cleaners • • •b •Hydrocarbon/Surfactant Blends • •HCFCs • • • •HCFCs & HFEs • • • • • •Low Flash Point Solvents •b •b •b •b •b •b

Low Vapour PressureSolvent Blendsa • •b •b •P-Chlorobenzotriflouride •b •b

Media Blasting •Steam •Volatile Methyl Siloxanes •b •b •b

a) Non-halogenated mixtures b) With appropriate flammability protection c) Includes agitation such as ultrasonics, mechanical, etc. d) With reasonable containment

Viable alternatives to metal cleaning ozone-depleting solvents


28

regulated as VOCs. Many hydrocarbon solvents are toxic, especially those with an aromatic molecular

structure. Some are carcinogenic or mutagenic. The toxicology of oxygenated derivatives is very

complex: some are very toxic, others much less so.

Many solvent blends are available for manual cleaning and for cold immersion cleaning.


Aqueous cleaners are potential substitutes for CFC-113 and 1,1,1-trichloroethane in metal

degreasing. The process involves washing, rinsing and drying. Aqueous cleaning uses immersion with

mechanical agitation, ultrasonic or spray processes. Each requires different equipment with optional

features such as heaters, dryers, automation equipment, filtration, recycling and water treatment.

Proper waste disposal is important in aqueous cleaning, because some by-products are not

biodegradable. Aqueous cleaning is more energy-intensive than solvent cleaning and thus has a larger

global warming impact. Ultrasonic cleaning is appropriate only for small parts and becomes inefficient

if the water contains dissolved gases.

Emulsion cleaners and hydrocarbon/surfactants are used in semi-aqueous cleaning and have many

different formulations. They are used with ultrasonic agitation and fluid circulation to clean metal parts.

Their advantages are low vapour pressures, low evaporation loss, low flammability and high flash

points. However, they have associated recycling and disposal problems, low contaminant-saturation

capacity and require special equipment. Also, they are frequently highly alkaline, imposing strict health

and safety measures. Aqueous immersion and solvent emulsions in semi-aqueous processes can be

used in all metal-cleaning operations. Tubing, complex shapes and sensitive materials all require

specially designed equipment tailored for that specific process.

Various mechanical cleaning methods have been used for metal surface preparation and have been

proposed as possible alternatives for CFC-113 and 1,1,1-trichloroethane. Brushing, wiping with rags

or sponges, use of absorbent materials, media blasting and pressurized gases are generally best

suited for lower grade cleaning requirements or as a pre-cleaning operation in the removal of solid

and semi-solid soils. Pressurized gas (air, rare earth gases, carbon dioxide, and nitrogen) may be used

for particulate contamination. The compressed air typically found in workshops is totally unsuitable for

this application because – unless a suitable filter and drier are used – it is frequently heavily

contaminated with entrained water and compressor oil. Specific technologies under development

include wheat starch, sodium bicarbonate, and solid carbon dioxide blasting.

So called “no-clean” options for metal degreasing include water-soluble, emulsifiable machining and

metal forming lubricants (chlorinated or not). They are much easier to remove with aqueous cleaners

and not hazardous to workers. The true “no-clean” methods are rarely used and consist of volatile

pressing and cutting oils (so-called “vanishing oils”).

KEY FACTS

Substitute solvents:

• chlorinated solvents (trichloroethylene, perchloroethylene, methylene chloride)

• aliphatic and aromatic hydrocarbons

• oxygenated hydrocarbon derivatives

• HCFC blends

Not-in-kindtechnologies:

• aqueous cleaning• semi-aqueous

cleaning• mechanical cleaning• vacuum de-oiling• "no-clean" options


29

Dry cleaning

Substitute solvents

The new generation of higher flash point hydrocarbon solvents (HCs) that have lower odour and

toxicity are the most suitable substitute for CFC-113 dry cleaning.

A small number of machines using HCFC-141b and HCFC-225 are in use and are effective

substitutes for dry cleaning. These solvents are, however, defined as transitional substances under

the Montreal Protocol and should only be used with sophisticated recovery systems.

Perchloroethylene is the most widely used dry cleaning solvent in the world, although it is not suitable

for all dry cleaning due to its solvency power. It can be used safely in specially developed new super

tight machines. These incorporate newly designed carbon adsorption systems that further reduce the

already frugal solvent consumption. Some authorities consider it to be a possible human carcinogen

but most agree that there is a low risk to humans under normal conditions of use. Perchloroethylene

is also the most suitable substitute for 1,1,1-trichloroethane for hand application to remove machine

oil stains caused during garment manufacture.

Gentle wet cleaning is a useful adjunct to dry cleaning but, due to its tendency to shorten the life of

structured wool jackets and coats, it is only suitable for a proportion of the cleaning classifications.

Article 5 countries

There are no known CFC-113 machines installed in Article 5 countries, but CTC and 1,1,1-

trichloroethane are used. Depending on the level of soiling of the articles requiring cleaning,

perchloroethylene or hydrocarbon solvents are the recommended substitutes. For medium to heavily

soiled work perchloroethylene should be used. Hydrocarbons are suitable for lightly soiled work,

delicate colours and beaded garments. Many dry cleaning machine manufacturers produce basic

machines suitable for developing countries.

Large quantities of CTC are being used in Article 5 countries. Use of CTC in non-Article 5 countries

was ended some 30-40 years ago on health and safety grounds. CTC is a probable human

carcinogen as well as having high ODP. Substitution with perchloroethylene or hydrocarbon should

be arranged as soon as practicable. This will require replacement of CTC machines, as they will be

unsuitable for safe conversion.

KEY FACTS

• Phase out option currently linked to replacement by hydrocarbon

• Super-tight perchloroethylene dry cleaning machines are available for more soiled fabrics

• Short-term conservation is by improved operating practices and maintenance

• Phase out of carbon tetrachloride (CTC) in developing countries should be expedited

• Suitable lower cost hydrocarbon or perchloroethylene models are available for developing countries

• Waste residues should be contained for recycling/ incineration according to local regulations


30

Adhesives

Substitute solvents

The solvents used for adhesives are of following types:

• Toluol, xylol and other aromatic hydrocarbons;

• Aliphatic hydrocarbons, such as white spirit, hexanes;

• Ester, ketone, glycol ethers;

• Hydrochlorocarbons, mainly methylene chloride;

• Hydrobromocarbons, essentially n-propyl bromide.

They are suitable for dissolving polymers such as polyvinylacetate and co-polymers, natural and

synthetic rubbers, nitrocellulose, acrylics and polyurethane. Almost all conventional organic solvents

are VOCs and their use is restricted in several countries, requiring expensive ventilation and vapour

recovery equipment. Some of the above mentioned solvents are flammable and require flameproof

equipment and extraction systems for safe handling. Some aromatic hydrocarbons are toxic. The

hydrohalocarbons are used to replace 1,1,1-trichloroethane. While n-propyl bromide is considered a

‘drop in’ alternative, the faster evaporation rate of methylene chloride requires significant formulation

adjustment to achieve the same adhesive application level. This is especially true with sprayed

adhesives.


Water-based adhesives: a large number of adhesives use water instead of organic solvents. A water-

based adhesive can be a solution, latex or an emulsion. Latex adhesives are more likely to replace

solvent-based adhesives than solution adhesives because their synthetic binders provide more

versatility and higher performance. Water-based adhesives perform well on many surfaces especially

non-porous to porous bonding and moist surfaces.

Hot melt adhesives: hot melts are primarily 100 per cent solid thermoplastic bonding materials that

achieve a solid state and resultant strength upon cooling. The major applications are bookbinding,

packaging, textiles and product assembly including construction glazing and automotive door panel

and carpet installation. Hot melt adhesives applications are, however, limited. They have poor

adhesion to a number of substrates, creep under load over time and, at elevated temperatures, have

limited strength and heat resistance.

Radiation cured adhesives: radiation curing is a production technique for drying and curing adhesives

through the use of radiant energy: ultraviolet (UV), infrared (IR), electron beam (EB), gamma and x-

rays. The binding agents that can be cured include acrylics, epoxies, urethanes, anaerobic adhesive

and polyester resins. Applications include electronics, communications and consumer products,

transportation, packaging, medical and dental uses, and pressure sensitive tapes. One drawback is

that adhesive curing is only possible in the ”line of sight” of the radiant energy, unless the adhesive is

designed to release free radicals on irradiation, starting a chain reaction to the “hidden” areas.


31

High solids adhesives: high solids have good performance characteristics, including initial bond

strength, comparable to that of 30 per cent solids adhesives in medium and high demand

applications and can be applied using existing equipment at normal line speeds with minor

modifications. In other application areas, such as bonding of rubber assemblies, high solids

adhesives have not been as successful. High solids adhesive films are too thick for bonding of

rubber assemblies, resulting in limited versatility and generally poor performance.

Powders: one-part epoxies, urethanes, and natural resins are often supplied as powders that require

heat to cure. Powders are used only for non-pressure-sensitive applications. One advantage of the

powder form is that no mixing or metering is necessary. However, powders must be refrigerated to

maximize shelf-life.

Non-volatile solids and liquids and reactive liquids: moisture-cured adhesives and reactive liquids can

be applied as 100 per cent non-volatile solid and liquid systems. These adhesives are composed

entirely of binding substances, modifiers, and fillers (i.e. they have no carrier or solvent). Some two-

component adhesives use reactive solvents that form part of the cured mass and thus do not

depend on evaporation. Reactive liquids are used for high performance structural applications.

KEY FACTS

• Complete elimination of

ozone-depleting solvents

is possible

• Several substitutes

• Water-based adhesives

• Hot melts

• Radiation cured

adhesives

• High solids and powders

• Non-volatile solids and

reactive liquids


32

Coatings and inks

Use of 1,1,1-trichloroethane as a solvent for binding substances in decorative coatings and inks

increased in the late 1980s, as it was used to replace VOC solvents in coating and ink formulations.

However, even at its peak, 1,1,1-trichloroethane use in this sector was not more than 1 per cent of

total consumption. CFC-113 use has always been much less and is considered negligible. The trend

towards increased use of 1,1,1-trichloroethane has reversed in recent years as the solvent came

under the Montreal Protocol. A number of suitable replacement solvents and formulations are now

available.

Substitute solvents

Many different conventional non-halogenated linear or cyclic hydrocarbon solvents can be used in

place of 1,1,1-trichloroethane for coatings and inks, for example, alcohols, esters, xylol, terpenes or

ketones. These solvents or blends of them are very capable of dissolving the binding resin systems.

However, there are significant drawbacks. From a safety perspective, these solvents require warning

labels for users accustomed to the non-flammable 1,1,1-trichloroethane products. Storage and

distribution methods may also have to be altered to complete a conversion to flammable

solvents/products. Because of both VOC and flammability concerns, there is a trend towards an

increased use of water-based products.


Water-based: Water-based, high solids and powder formulations can be used in place of 1,1,1-

trichloroethane and other solvents to produce coatings and inks. Recent advances in water-based

coating technology have improved the dry-time, durability, stability, adhesion, and application of

water-based coatings.

High solids: Although high-solid coatings resemble conventional solvent coatings in appearance and

use, high-solid coatings contain less solvent and a greater percentage of resin. They are applied using

methods similar to those used for water-based coatings. High-solid coatings can be used for

appliances, metal furniture, and heavy construction equipment. They are applied using dipping, flow-

coating, air or airless atomizing, air or airless electrostatic spraying, rotating disks and bells, rolling,

continuous coating, centrifugal coating and tumbling.

Powder: Powder coatings contain the resin only in powder form and thus have no solvent. They are

applied using fluidized beds, electrostatic spray, and electrostatic fluidized beds. The object to be

coated is heated above the powder's melting point, so that when the object is removed from the

presence of heat, the resin fuses into a continuous film. The resin then hardens to form a finish that

has excellent durability and corrosion resistance.

UV/EB-cured: UV/EB-cured coatings and inks have been used in very limited applications over the

last 20 years, but their use has seen a dramatic increase in recent years. There are several factors

that contribute to the growing popularity of UV/EB-cured coatings and inks. These include high

quality, rapid cure times, and low energy use. One major limitation to the use of UV/EB-cured

coatings and inks is outdoor durability.


33

Aerosols

Substitute solvents and carriers

Replacement technologies include petroleum distillates, non-ozone-depleting chlorinated solvents,

HCFCs, HFCs and HFEs, alcohols, other organic solvents, and water-based formulations. When

evaluating the alternatives, three performance factors are considered of most importance: toxicity,

flammability and density. Flammability is a major concern for petroleum distillates, alcohols, and other

non-halogenated organic solvents. The lower density of these same solvents increases the tendency

of solid ingredients to settle and requires larger containers to deliver a similar weight of product. It is

also important to consider the flammability of the aerosol propellant and bear in mind that many

alternative solvents are classified as VOCs, which may restrict their use in some geographic areas.

Petroleum distillates and other non-halogenated organic solvents are used for various automotive

products such as tyre cleaners, lubricants, spray under-coatings, and in household products such as

water repellents/shoe water-proofers, glass frostings, and insecticides. These and other flammable

organic solvents, including alcohols, ketones, and terpenes, are attractive alternatives due to their

strong cleaning power, coupled with an ability to dissolve other active ingredients.

Non-ozone-depleting chlorinated solvents including trichloroethylene, perchloroethylene, and

methylene chloride may be used in limited applications. Their primary benefits are non-flammability

and high solvency. However, potential formulators and users of aerosols containing these solvents

must be aware of their associated human health risks.

HCFC solvents have much the same properties as CFC-113 and 1,1,1-trichloroethane, making them

ideal replacements from a technical standpoint. However, both HCFC-141b and HCFC-225 have low,

but finite, ODPs and have a phase out date that will limit their future use. Some countries already

forbid their use in aerosol products.

HFC and HFE compounds are non-flammable and have low toxicity, good stability and compatibility

with many metals and synthetic materials. However, HFCs and HFEs have relatively low solvency, are

more expensive than other options and have GWP. Aerosol packagers often blend these compounds

with hydrocarbons, alcohols, chlorocarbons, and ketones to enhance their cleaning and carrier

performance. These partially fluorinated solvents are used for cleaning of operating electrical contacts,

because of their non-flammability.

Available water-based products include shoe polishes, insecticide foggers, mould release agents,

and fabric protectors. Some of these products may have reduced overall effectiveness due to

reduced dispersion of the propelled liquid, long drying time, and inability to sufficiently wet the surface

being sprayed.

Alternative delivery systems

The use of ozone-depleting solvents in aerosol products could be eliminated if alternative delivery

methods are adopted. Some are already available, such as the use of brushes, vacuum enclosure

cleaning for brakes and greater use of professional dry cleaners instead of aerosol spot-removers. In

some cases – where the ozone-depleting solvent is used only as a solvent or carrier and not as an

active ingredient – it may be possible to reformulate the aerosol product to function without the use of

a solvent. Such formulations are available for tooling release agents, with improved performance in

some applications. However, it is also possible that performance may be lower, primarily because of

uneven dispersion of the active ingredient.

KEY FACTS

1,1,1-Trichloroethane and

CFC-113 used in aerosols

can be replaced by

petroleum distillates,

non-ozone depleting

chlorinated solvents,

HCFCs, HFCs and HFEs,

alcohols, other organic

solvents, water-based

formulations, and

alternative delivery

systems.


34

Miscellaneous uses

Alternatives for selected applications (A full discussion of more ‘exotic’ miscellaneous uses can be

found in the latest 1998 STOC manual).

Oxygen system cleaning: the use of oxygen involves a degree of risk because oxygen vigorously

supports combustion when in contact with many substances. A high level of cleanliness is therefore a

prerequisite for oxygen system components. Examples of alternatives to CFC-113 include aqueous

cleaning with certain parts requiring ethanol, and solvent blends containing HFEs, HFCs, and HCFCs.

Detection of latent fingerprints: several alternatives have been evaluated for the ninhydrin reagent

fingerprint detection technique. Some alternatives such as HCFC-141b, HCFC-225ca/cb,

hydrocarbons and alcohols can be used, but they are not as effective as CFC-113. The most

common problems have been fading of ink, toxicity or flammability. Recently, HFC and HFE blends

have been used with excellent results. Similarly, UV-sensitive fingerprint detectors have successfully

converted from CFC-113 to HFC/HFE products.

Laboratory testing: CFC-113, 1,1,1-trichloroethane, and CTC are used for analyses in laboratories or

investigations. Many uses of ozone-depleting solvents in laboratory applications have been granted

global exemption. However, alternatives have been found for testing of oil, grease, and total

petroleum hydrocarbons in water and testing of tar in road paving materials.

Semiconductor manufacturing: FCs (and possibly some CFCs) used in plasma etching may be able

to be replaced with an HFC or HCFC while potential newer process alternatives include mixtures of

various fluorocarbons and HFCs with non-ozone-depleting chlorine sources. Most of these materials

are destroyed during the plasma generation process, which greatly limits their impact on the

environment.

Fabric protection and coating: alternative non-aerosol fabric protection products applied at the mill or

by the retailer include organic solvents that extend the dry time and are flammable. These products

may require additional capital expense if solvents are to handled and used safely. A water-based

fluorocarbon resin system has been introduced recently that will replace solvent-based fluorocarbon

products currently used for this application. The system will require the purchase of special equipment

for the application of the water-based product.

34


35

Article 5 Countries

Choosing the best alternative

The previous sections have provided an outline of the many substitute solvents and other not-in-kind

cleaning technologies available to enterprises in Article 5 countries. Fortunately, alternatives now exist

for all but a tiny number of extremely high-tech uses. In fact, there are so many options for most

applications that choosing the best available alternative can be challenging. Even within a given

solvent sub-sector, many different advantages and disadvantages exist between the options.

The selection of the alternative should be based on five primary factors given below (in order of

importance). The alternative:

(1) should not be an ozone-depleting substance;

(2) should enable the enterprise to maintain a product reliability level at least equal to the past

methods;

(3) should be economical;

(4) should not create significant environmental impact; and

(5) should not compromise worker or consumer health and safety.

To assist Article 5 country enterprises with their decision, the following hierarchy of alternative classes

(in order of preference) has been assembled, taking account of these five primary factors :

• "No-clean", keep-clean;

• Aqueous cleaning;

• Hydrocarbon-surfactant (“semi-aqueous”) cleaning;

• Organic solvent cleaning (with solvents less toxic than non-ozone-depleting conventional

halogenated solvents);

• Non-ozone-depleting conventional halogenated solvents (TCE, MC, PCE);

• Organic solvent cleaning (with solvents more toxic than non-ozone-depleting conventional

halogenated solvents);

• HFCs and HFEs;

• HCFC-225;

• HCFC-141b;

• PFCs.

Experience thus far has shown that most conversions involving new equipment have been to aqueous

or hydrocarbon-surfactant cleaning. However, for enterprises considering retrofits of existing equipment,

conventional chlorinated solvents offer the only economical solution. Although HCFCs, HFCs, and HFEs

may work technically, the solvent cost remains prohibitive for use in a typical retrofit vapour degreaser.

Retrofits to aqueous and hydrocarbon-surfactant cleaning are also possible. Degreaser tanks are

sometimes retrofitted for water based cleaners, but this requires extensive engineering redesign and

should not be attempted without direct consultation with a qualified equipment supplier. For

hydrocarbon-surfactant processes, the chemical manufacturer must also be consulted.


36

Conservation and recovery

The Montreal Protocol controls only the importation and production of ozone-depleting substances.

Recovery and recycling are not included, and therefore provide a major incentive for the solvents

industry to improve conservation and recovery practices. Any reduction in current levels of

consumption using such methods will contribute significantly to achieving the goals of the Protocol.

Improved conservation and recovery protects the ozone layer, the local environment, and the health of

workers, as well as improving efficiency and saving money. Some countries are introducing specific

measures to encourage better practices, over and above those required by the Protocol.

Conservation and recovery practices are effective short-term solutions while longer-term solutions are

being selected.

General steps

Some of the main sources of emissions in the major sectors of the solvents industry are: diffusive and

convective losses of solvent vapour from equipment; leaks from equipment and connective piping;

and liquid drag-out on work being processed. Older equipment is generally less efficient and more

likely to emit solvents, but can sometimes be retrofitted with containment devices. Seven general

steps can be taken by most companies to reduce solvent consumption and emission:

• eliminate unnecessary cleaning; consolidate and centralize all cleaning processes, and use fewer

machines where possible;

• isolate open sources of emissions, to give reductions of 50–80 per cent. Open-top vapour

degreasers can be retrofitted to include covers and hoists;

• eliminate all sources of draughts over the vapour-air interface of the machines, turn off all “lip vent

exhausts”;

• match the workload size and weight to the cross-sectional area of the tanks and heating capability

of the cleaning equipment;

• automate vapour degreasing and other processes – this can reduce solvent emissions by 20–30

per cent;

• educate managers and operators about the financial and environmental costs of using ozone-

depleting solvents, and about better procedures – these changes can reduce emissions by about

30 per cent;

• maintain equipment according to manufacturers’ specifications and eliminate all leaks – thus

reducing solvent loss by up to 20 per cent.


37

Specific measures

In the electronics industry, solvent losses can account for 90 per cent of total consumption, so

recovery measures should be adopted wherever possible. Drag-out losses contribute significantly to

overall emissions. Using automatic handling equipment to feed parts into the vapour degreasers at a

constant rate to produce an effective cycle can reduce solvent losses. Better basket and rack design

can also reduce drag-out in electronics cleaning. Fans used to cool parts after soldering can ensure

that circuit boards enter cleaners at temperatures that minimize evaporation.

Good practices specific to general metal cleaning include: manual removal of large contaminants

before degreasing with solvent and adding sophisticated filtration equipment; gravity separation; water

adsorption; and single plate distillation. Vapour blanket collapse in general metal cleaning is often

caused by introducing items with a large thermal mass. When the vapour blanket re-forms, air

saturated with solvent vapours is expelled, causing large solvent loss.

External reclamation and recycling services are often available to purify contaminated solvent and

return it to the original customer or sell it to other users. An example of such downstream reuse

would be selling solvent from an electronics cleaning process into the dry cleaning industry. On-site

recycling is especially economical if the soiled solvent from several machines is piped to a single still

for recycling. This is viable only when all the cleaners are removing the same soil with the same

solvent formulation.


38

Reduction scenarios

Non-Article 5 countries

Non-Article 5 countries have phased out ozone-depleting solvents since the beginning of 1996. CTC

was not used as an industrial solvent and 1,1,1-trichloroethane produced in 1995 has reached the

end of its shelf life, although there may still be some recycled solvent in use. Minor use of stockpiled

CFC-113 continues. However, users are feeling increasing pressure to find alternatives as stockpiles

run out. A very small quantity of ozone-depleting solvent, authorized for Essential Use Exemptions, is

still produced. Use of transitional solvents HCFC-225 and HCFC-141b may continue until as late as

2030. The recent availability of HFCs & HFEs has made it technically feasible to phase out HCFCs in

all but a small number of applications. However, the higher price of these alternatives may delay

conversion from HCFCs until later years.

Article 5 Countries

Many Article 5 countries have made impressive progress in phasing out ozone-depleting solvents.

Some countries have been phasing out solvents for several years. Conversely, others have continued

to increase production and use right up to the mid 1999 freeze.

The primary phase out challenge is no longer technical in nature. The technology was developed and

implemented to support the 1996 phase out in non-Article 5 countries. For Article 5 countries it is a

matter of identifying, informing and, where necessary, assisting the many thousands of ozone-

depleting solvent users. Excellent coordination between government and industry will be required to

ensure a smooth transition from CFC-113 and CTC (by 2010) and TCE (by 2015) to the multitude of

possible alternatives.

Specific challenges for Article 5 countries and their industries include the following:

• identification of producers, importers and vendors of ozone-depleting solvents;

• identification of products that contain ozone-depleting solvents;

• identification of and assistance to users from many small and medium size enterprises in selecting

and converting to the most appropriate alternative (most difficult in the solvents sector);

• affordability of cost of alternatives, including new or retrofit equipment and, in some cases, higher

operating expenses for the converted process.

It is generally recognized that, compared to other sectors, phase out in the solvents sector is slower

due to a multitude of applications over about 16 sub-sectors in a number of diverse industries. Large

international companies in Article 5 countries face few serious barriers to the phase out process. A

major effort remains for small and medium size enterprises which, when taken collectively, consume

the greatest volume of ozone-depleting solvents.


39

Efficient dissemination of technical and commercial information will be another challenge to a

successful phase out of ozone-depleting solvents. Much inefficiency has arisen in past efforts

because of poor distribution of information. For example, although the Internet contains much useful

and impartial information, it also publishes the ideas of vested interests and extremist views. Article 5

countries will need enough technical expertise to evaluate the information supplied and, if there are

any contradictions, to obtain impartial advice from reliable third parties.

As planned, the transitional HCFC solvents will remain in use longer. Production levels will not be

frozen until 2016 and may continue until 2040. Once again, phase out of these solvents is technically

feasible now. However, many of the alternative substitutes are much more expensive. The sooner this

cost disparity is bridged, the sooner phase out will be possible.

Illicit trade

Non-Article 5 countries have been fighting illicit trade since shortly after the 1996 phase out. The

problem is very difficult to control for a number of reasons. There is hope that, as the number of

countries producing ozone-depleting solvents drops, the sources of illicit trade will also decline.

However, countries that most recently “phase out” use of ozone-depleting solvents will have to guard

against becoming the next high-demand customer for illegal imports. Identification of remaining users

will be invaluable to the effort to control illicit trade.


40

Secretariats and Implementing Agencies

Multilateral Fund Secretariat

Dr. Omar El Arini

Chief Officer

Secretariat of the Multilateral Fund for

the Montreal Protocol

27th Floor, Montreal Trust Building

1800 McGill College Avenue

Montreal, Quebec H3A 6J6

Canada

Tel: 1 514 282 1122

Fax: 1 514 282 0068

E-mail: [email protected]

Web site: www.unmfs.org

UNEP Ozone Secretariat

Mr. Michael Graber

Acting Executive Secretary

UNEP Ozone Secretariat

PO Box 30552

Gigiri, Nairobi

Kenya

Tel: 2542 623-855

Fax: 2542 623-913

Email: [email protected]

Web site: www.unep.org/ozone

UNEP

Mr. Rajendra M. Shende, Chief

Energy and OzonAction Unit

United Nations Environment Programme

Division of Technology, Industry and Economics

(UNEP DTIE)

39-43 quai Andre Citroen

75739 Paris Cedex 15

France

Tel: 33 1 44 3714 50

Fax: 33 1 44 3714 74


Web site: www.uneptie.org/ozonaction

UNDP

Dr. Suely Carvalho, Deputy Chief

Montreal Protocol Unit, EAP/SEED

United Nations Development Programme

(UNDP)

304 East 45th Street

Room FF-9116,New York, NY 10017

United States of America

Tel: 1 212 906 6687

Fax: 1 212 906 6947


Web site: www.undp.org/seed/eap/montreal

UNIDO

Mrs. H. Seniz Yalcindag, Chief

Industrial Sectors and Environment Division

United Nations Industrial Development

Organization (UNIDO)

Vienna International Centre

P.O. Box 300

A-1400 Vienna

Austria

Tel: (43) 1 26026 3782

Fax: (43) 1 26026 6804


Web site: www.unido.org

World Bank

Mr. Steve Gorman, Unit Chief

Montreal Protocol Operations Unit

World Bank, 1818 H Street NW

Washington DC 20433

United States of America

Tel: 1 202 473 5865

Fax: 1 202 522 3258


Web site: www.esd.worldbank.org/mp/home.cfm

Resources


41

Contact points

European Chemical Industry Council (CEFIC)

Avenue Van Nieuwenhuyse, 4 box 1

B-1160 Brussels, Belgium

Phone: +32 2 676 7211

Fax: + 32 2 676 7300

e-mail general mailbox: [email protected]

Web site: http://www.cefic.org/

Friends of the Earth (FOE)

1025 Vermont Ave. NW

Washington, DC 20005 USA

Tel: +1 877 843 8687 or +1 202 783 7400

Fax: +1 202 783 0444

e-mail: [email protected]

Halogenated Solvents Industry Alliance, Inc.

2001 L Street NW

Washington, DC 20036

Tel: +1 202 775 0232

Fax: +1 202 833 0381

E-Mail: [email protected]

Japan Industrial Conference for Ozone Layer

Protection (JICOP)

Hongo-Wakai Bldg.

2-40-17, Hongo

Bunkyo-ku

Tokyo 113-0033

Japan

Telephone: +81 3 5689 7981 or 7982

Fax: +81 3 5689 7983

E-Mail: [email protected]

Equipment

The following categories of ozone-safe

equipment and solvents are now commercially

available. A full list of manufacturers and vendors

for each sector can be obtained from the

Thomas Register at

http://www.thomasregister.com/

Conservation and recovery

Licensed solvent recycling equipment

Carbon adsorption equipment

Emissions monitoring equipment

Vapour degreasing equipment

Precision cleaning

Alcohol cleaning equipment

Alternative solvents

Aqueous cleaners

Aqueous cleaning equipment

Hydrocarbon/surfactants

Plasma cleaning systems

Supercritical carbon dioxide

Ultraviolet light/ozone cleaners

Electronics assembly defluxing

Aqueous cleaners


Hydrocarbon/surfactant cleaners

Hydrocarbon surfactant equipment

Waste water treatment equipment


Alcohol cleaning equipment

Alternative organic solvents

Aqueous cleaners


Hydrocarbon/surfactant cleaners

ozone-depleting solvent products

and manufacturer names

It can be difficult to identify products containing

ozone-depleting solvents. As opposed to

refrigerated gases, halons, aerosol propellants,

some foam blowing agents and other ozone-

depleting substances, the ozone-depleting

solvents are shipped and labelled in identical

ways to hundreds of those that are not ozone

depleting. Users, agents, ozone officers,

customs officers and others are directed to a

STOC recommended web site that will help to

identify ozone-depleting solvent products that fall

under the regulations of the Montreal Protocol:

http://www.protonique.com/

unepstoc/stocfile/stocrr.htm


42

Further reading

The following six UNEP Technical Options Committees reports can be found at:

http://www.teap.org/

1998 Assessment Report of the Aerosols, Sterilants, Miscellaneous Uses and Carbon Tetrachloride

Technical Options Committee

1998 Assessment Report of the Flexible and Rigid Foams Technical Options Committee

1998 Assessment Report of the Halons Technical Options Committee

1998 Assessment Report of the Methyl Bromide Technical Options Committee

1998 Assessment Report of the Refrigeration, Air Conditioning and Heat Pumps Technical

Options Committee

1998 Assessment Report of the Solvent, Coatings and Adhesives Technical Options Committee


43

Glossary

adsorption surface phenomenon in which substances form physiochemical bonds with

other materials.

alcohol hydrocarbon derivatives with at least one hydrogen atom replaced by -OH.

aqueous cleaning cleaning with water to which suitable detergents, saponifiers, or other

additives may be added.

Article 5 country a Member State or Party to the Montreal Protocol, defined as a developing

nation according to criteria in Article 5, paragraph 1, of the Protocol and

which enjoys certain privileges in the phase out timetable.

azeotrope chemical mixture where vapour and liquid composition are identical.

biodegradable products easily broken down by living organisms.

brominated solvents unregulated ozone-depleting solvents, represented at the time of writing,

mainly by bromochloromethane and n-propyl bromide.

CFC chlorofluorocarbon.

CTC carbon tetrachloride.

carbon tetrachloride chlorocarbon solvent with an ODP of approximately 1.1. Also considered

toxic and a human carcinogen.

carcinogen causing cancer in animals and humans.

bromochloromethane see brominated solvents.

closed-top vapour a vapour degreaser designed so that the solvent and its vapour are

degreaser separated from the external atmosphere. Also known as low-emission,

airtight or zero-emission vapour degreaser.

combustible property of a product whose flash point is fixed at over 50°C (arbitrary limit).

detergent product designed to render soils soluble in water, usually made from

synthetic surfactants.

distillation means for purifying solvents by boiling into a vapour and collecting the

vapour condensate.

dry cleaning common term for cleaning textiles in organic solvents, as opposed to water.

emulsion suspension of very fine droplets of one liquid in another, where the two

liquids are normally immiscible.

ester fruity smelling acid derivative obtained by exchanging replaceable hydrogen

for alkyl radicals; used as solvents or artificial fruit essences.

flux chemical employed in soldering to facilitate solder joint production, often

rosin-based.

flammable property of a product whose flash point is fixed at under 50°C (arbitrary

limit).

flash point temperature at which a substance ignites on contact with a flame.

GWP global warming potential (potential of a substance to contribute to the

greenhouse effect).

glycol loose term for a diol or a dihydric alcohol, i.e. one containing two –OH

groups per molecule.

HCFC hydrochlorofluorocarbon.

HFC hydrofluorocarbon.

HFE hydrofluoroether.

halocarbon organic substance where at least one hydrogen atom has been replaced by

a halogen atom (fluorine, chlorine, bromine, iodine, or astatine).


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hydrocarbon organic substance made of hydrogen and carbon.

hydrocarbon/ less volatile hydrocarbon solvents.

surfactant blend mixed with surfactants that can be used in two-phase cleaning, with water

(semi-aqueous cleaning).

ion electrically charged particle.

Kauri-Butanol index used to provide an indication of a solvent’s soil solubilization ability.

ketone very reactive compound containing a carbonyl group, that may be formed by

oxidation of secondary alcohols.

low-solids flux flux containing little solid matter, eliminating the need for cleaning.

naphtha hydrocarbon mixture, usually a cut between gasoline and kerosene.

neutralizer substance added to balance the acid/alkaline content of water.

‘No-clean’ flux soldering flux whose residues are designed to be safe for certain

applications, without requiring a cleaning operation.

non-ionic uncharged.

n-propyl bromide see brominated solvents.

ODP ozone-depletion potential.

organic compound containing carbon and hydrogen.

ozone gas formed from three oxygen atoms.

PCB printed circuit board.

perchloroethylene chlorocarbon solvent used extensively in industrial degreasing and dry

cleaning.

polar molecule in which electric charges are unbalanced.

precision cleaning cleaning of high-precision mechanical parts, optical parts and electronic

sensors, as opposed to general metal cleaning.

rosin solid rosin made from pine-tree resin.

saponifier chemical that reacts with organic fatty acids (such as rosin), oils and greases

to form water-soluble alkaline soaps, mineral- or organic-based.

semi-aqueous solvents another name for hydrocarbon/surfactant (HCS) solvents.

solvent liquid in which another substance (the solute) is dissolved to form a solution.

SMT surface mount technology of printed circuit boards.

surfactant chemical that reduces water surface tension to enable cleaning.

terpene any homocyclic hydrocarbon with a formula C10H16.

vapour phase cleaning cleaning process where final rinse is achieved by condensing solvent vapour

on parts being cleaned.

ultrasonic cleaning immersion cleaning to maximize cleaning efficiency using high frequency

sound waves to create cavitational implosions close to parts.

VOC volatile organic compound – constituents will evaporate at temperature of

use, and may react photochemically with atmospheric oxygen to produce

toxic and smog-producing tropospheric ozone.

wave soldering mass soldering electronics assemblies after fluxing by passing them through

a wave of molten solder.

water-soluble flux flux where post-solder residue can be removed by water – usually very

active – also known as organic acid fluxes.

zero emissions

vapour degreaser see closed-top vapour degreaser.


45

About the UNEP DTIE OzonAction Programme

Nations around the world are taking concrete actions to reduce and eliminate production and

consumption of CFCs, halons, carbon tetrachloride, methyl chloroform, methyl bromide and HCFCs.

When released into the atmosphere these substances damage the stratospheric ozone layer – a

shield that protects life on Earth from the dangerous effects of solar ultraviolet radiation. Nearly every

country in the world has committed itself under the Montreal Protocol to phase out the use and

production of ODS. Recognizing that developing countries require special technical and financial

assistance in order to meet their commitments under the Montreal Protocol, the Parties established

the Multilateral Fund and requested UNEP, along with UNDP, UNIDO and the World Bank, to provide

the necessary support. In addition, UNEP supports ozone protection activities in Countries with

Economies in Transition (CEITs) as an implementing agency of the Global Environment Facility (GEF).

Since 1991, the UNEP DTIE OzonAction Programme has strengthened the capacity of governments

(particularly National Ozone Units or “NOUs”) and industry in developing countries to make informed

decisions about technology choices and to develop the policies required to implement the Montreal

Protocol. By delivering the following services to developing countries, tailored to their individual needs,

the OzonAction Programme has helped promote cost-effective phase out activities at the national and

regional levels:

Information Exchange

Provides information tools and services to encourage and enable decision makers to make informed

decisions on policies and investments required to phase out ODS. Since 1991, the Programme has

developed and disseminated to NOUs over 100 individual publications, videos, and databases that

include public awareness materials, a quarterly newsletter, a web site, sector-specific technical

publications for identifying and selecting alternative technologies and guidelines to help governments

establish policies and regulations.

Training

Builds the capacity of policy makers, customs officials and local industry to implement national ODS

phase out activities. The Programme promotes the involvement of local experts from industry and

academia in training workshops and brings together local stakeholders with experts from the global

ozone protection community. UNEP conducts training at the regional level and also supports national

training activities (including providing training manuals and other materials).

Networking

Provides a regular forum for officers in NOUs to meet to exchange experiences, develop skills, and

share knowledge and ideas with counterparts from both developing and developed countries.

Networking helps ensure that NOUs have the information, skills and contacts required for managing

national ODS phase out activities successfully. UNEP currently operates 8 regional/sub-regional

Networks involving 109 developing and 8 developed countries, which have resulted in member

countries taking early steps to implement the Montreal Protocol.


46

Refrigerant Management Plans (RMPs)

Provide countries with an integrated, cost-effective strategy for ODS phase out in the refrigeration and

air conditioning sectors. RMPs have to assist developing countries (especially those that consume

low volumes of ODS) to overcome the numerous obstacles to phase out ODS in the critical

refrigeration sector. UNEP DTIE is currently providing specific expertise, information and guidance to

support the development of RMPs in 60 countries.

Country Programmes and Institutional Strengthening

Support the development and implementation of national ODS phase out strategies especially for

low-volume ODS-consuming countries. The Programme is currently assisting 90 countries to develop

their Country Programmes and 76 countries to implement their Institutional-Strengthening projects.

For more information about these services please contact:

Mr. Rajendra Shende, Chief, Energy and OzonAction Unit

UNEP Division of Technology, Industry and Economics

OzonAction Programme

39-43, quai André Citroën

75739 Paris Cedex 15 France


Tel: +33 1 44 37 14 50

Fax: +33 1 44 37 14 74

www.uneptie.org/ozonaction.html

UNEP�


47

About the UNEP Division of Technology, Industry and Economics

The mission of the UNEP Division of Technology, Industry and Economics is to help decision-makers

in government, local authorities, and industry develop and adopt policies and practices that:

• are cleaner and safer;

• make efficient use of natural resources;

• ensure adequate management of chemicals;

• incorporate environmental costs;

• reduce pollution and risks for humans and the environment.

The UNEP Division of Technology, Industry and Economics (UNEP DTIE), with its head office in Paris,

is composed of one centre and four units:

• The International Environmental Technology Centre (Osaka), which promotes the adoption and use

of environmentally sound technologies with a focus on the environmental management of cities

and freshwater basins, in developing countries and countries in transition.

• Production and Consumption (Paris), which fosters the development of cleaner and safer

production and consumption patterns that lead to increased efficiency in the use of natural

resources and reductions in pollution.

• Chemicals (Geneva), which promotes sustainable development by catalysing global actions and

building national capacities for the sound management of chemicals and the improvement of

chemical safety world-wide, with a priority on Persistent Organic Pollutants (POPs) and Prior

Informed Consent (PIC, jointly with FAO).

• Energy and OzonAction (Paris), which supports the phase out of ozone depleting substances in

developing countries and countries with economies in transition, and promotes good management

practices and use of energy, with a focus on atmospheric impacts. The UNEP/RISØ Collaborating

Centre on Energy and Environment supports the work of the Unit.

• Economics and Trade (Geneva), which promotes the use and application of assessment and

incentive tools for environmental policy and helps improve the understanding of linkages between

trade and environment and the role of financial institutions in promoting sustainable development.

UNEP DTIE activities focus on raising awareness, improving the transfer of information, building

capacity, fostering technology cooperation, partnerships and transfer, improving understanding of

environmental impacts of trade issues, promoting integration of environmental considerations into

economic policies, and catalysing global chemical safety.

www.unep.orgUnited Nations Environment Programme

P.O. Box 30552 Nairobi, KenyaTel: (254 2) 621234Fax: (254 2) 623927

E-mail: [email protected]: www.unep.org

protecting the ozone layerfinal goal of effective global protection of the ozone layer is to be...

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